The Associated PressRepublican presidential candidate and former Speaker of the House Newt Gingrich went to battle with CNN anchor and debate moderator John King, along with the other candidates, at Thursday's South Carolina primary debate. (AP Photo/Charlie Neibergall)

John King's open marriage question to Newt GingrichGingrich tersely told King he didn't want to respond to the claim but he would anyway, then sharpy criticized the "negative" and "vicious" attacks he and other candidates get from mainstream media during the primary process.

"Let me be quite clear. The story is false," Gingrich said in response to King's question, according to The Associated Press.

CNN political analyst David Gergen called the heated exchange one of the most explosive moments in presidential debate history.

Do you think King's question was appropriate? After the debate, Gingrich told CNN's Anderson Cooper he thought King did a great job moderating, yet he found that question grossly inappropriate to open the discussion.

Watch the exchange:

King defended himself on CNN, calling it a "damned if do you, damned if you don't" moment. He said it was his decision alone to ask, and he wanted to deal with it at the top of the broadcast.